OLD oaks and maples shade the red brick walls of the experimental lab. There is a collegial feeling as if graduate students are working on advanced chemistry projects. But inside, scientists at E.I. du Pont de Nemours & Co. Inc. work 24 hours a day, analyzing chemicals that are produced from a maze of pipes and kettles. The Du Pont employees are trying to find the formula for a new generation of products to replace freon - the chemical that makes air conditioners and refrigerators work. Freon is a chlorofluorocarbon (CFC), a 51-year-old chemical, now known to be dangerous to the ozone layer - the layer in the upper atmosphere which filters out dangerous rays of the sun.
It is a race against time.
Despite the lack of commercially available substitutes, at least 20 states are considering 80 proposals to ban products that deplete the ozone layer. Typical is the state of Vermont which last month said it would not register any vehicle sold in the state or brought in from another state after the 1994 model year, unless it used a non-ozone depleting chemical in its air conditioner.
Cities are also joining in. Last month, Irvine, Calif., prohibited the use of CFCs in any industrial process except those used for medical or military use after July 1, 1990. Newark, N.J., is wrestling with a similar proposal.
Congress is on the same track. There are at least six bills in the Senate and one in the House of Representatives that will put a lid on CFCs. The sponsor of three bills, Sen. Albert Gore Jr. (D) of Tennessee, is proposing a 5-year phase out and a trust fund to find alternatives to CFCs.
The Senate Environment and Public Works Committee has already approved legislation authored by Sen. John Chafee (R) of Rhode Island. The legislation calls for the elimination of the most harmful CFCs by the year 2000 - roughly in line with what industry says it plans to do today.
Senator Chafee would also, however, put controls on CFCs which have had a hydrogen molecule added. Known as HCFCs, these chemicals have a shorter life span and cause less damage to the ozone layer. The chemical companies and producers view HCFCs as ``bridge chemicals'' which will get users through the mid-1990s until new formulas can be devised. ``We think it would be ill advised to put controls on them,'' says F.A. (Tony) Vogelsberg Jr., environmental manager for Du Pont.
On the House side, Rep. Jim Bates (D) of California wants to not only end production by July 1, 1996, but also ban CFC exports.
At the same time, Congress is considering an excise tax on CFCs. Rep. Pete Stark (D) of California has introduced legislation that is scaled to increase the tax depending on how much each different type of CFC depletes the ozone layer. The Joint Committee on Taxation estimates it will bring in $8.6 billion between 1990 and 1994. The legislation is already part of the tax package pending in the House Ways & Means Committee.
While Congress is debating, activists are stepping up the pressure on the grass-roots level. Last week, a coalition of environmental groups marched outside of Westinghouse Electric Corporation's plant in Linthicum, Md. They had identified the factory as the largest emitter of CFCs in the state from a 1987 Environmental Protection Agency filing. ``We're trying to raise people's consciousness,'' says William C. Walsh, staff attorney at US Public Interest Research Group, one of the sponsors.
Such consciousness raising has had an impact. Last week, General Electric Company agreed to cut back its future use of CFCs by 300,000 pounds yearly. The agreement came after Linda Draper, a housewife from Ellicott City, Md.,watched a GE repairman vent CFCs from her refrigerator into the atmosphere as part of a recall effort. After getting nowhere with GE, she contacted Sen. Gore, who negotiated an agreement with the company, which is a big employer in his state. ``You see there is something an individual can do,'' the senator said at a press conference.
Users of CFCs are taking notice. Last week, the Nissan Motor Company said it plans to make its air conditioners and manufacturing processes CFC-free by the year 1993. Nissan was followed quickly by the Honda Motor Company, which said it will terminate the use of CFCs by the mid-1990s.
On July 1, United States chemical companies began supplying customers with only 80 percent of their 1988 CFC usage. This cutback is part of the Montreal Protocol, which scales back CFC production to 1986 levels before gradually ending all use by the year 2000.
A big US consumer, American Telephone & Telegraph Company, also said last week it would stop using all ozone-depleting chemicals by the year 1994. Refrigerator and freezer manufacturers are forming a consortium to identify possible substitutes.
All of this activity is not lost on Du Pont, which supplies 50 percent of the CFCs used in the US and 25 percent used in the world. It has accelerated its research, spending $45 million this year, up from $35 million last year.
Du Pont researchers are optimistic. ``We're making a lot of progress,'' says N.M. (Malli) Rao, a research fellow at the experimental station. Du Pont's optimism is partially based on a gamble. It is running pilot plants even before it has completed toxicity testing.
It takes two years of testing toxicity on rats and a year and a half for a single pathologist to dissect and look at 36,000 slides. And there are disappointments all along the way. In 1987, Du Pont thought it might have a substitute for a chemical used as a solvent to clean microelectronic chips and medical products. After a 3-month test, the company discovered the new chemical was detrimental to the reproductive organs of male rats. ``We notified the Environmental Protection Agency, stopped doing the research on that product and started looking for other things,'' says C.A. (Tony) McCain, a manager at Du Pont.
The reason for the problems is simple. The original CFC formulation is very difficult to replace. CFCs, which were originally discovered by General Motors scientists in 1928, are very stable chemicals. Because they don't break down easily, workers and consumers can be exposed to them without worry.
This stability, however, means the chemicals don't break down until they reach the stratosphere. Once above the earth, the chlorine in the chemical helps destroy the ozone molecules there. Without the protection of the ozone layer, there would be an increase in the sun's ultraviolet rays reaching the earth's surface. This could increase the risk of cancer and cause crop damage, according to scientists.
Replacement chemicals don't quite do the same job. For example, Du Pont is now building a small plant to produce a fluorinated hydrocarbon (HFC), a chemical with no chlorine. In the late 1970s, Du Pont produced a small amount of the HFCs and inserted it into a standard refrigerator. For a decade, the machine kept workers' lunches cold without problems. Two years ago, the company dismantled the refrigerator. ``It looked great,'' says Philip Meredith, director of Freon Products Research & Development. But it was not as energy efficient as a CFC.
In fact, for many of the replacements for CFCs, there is a catch-22 effect. When CFC foam insulation used in refrigerated trucks is replaced with insulation made from fiberglass, the result is less usable storage space. With less usable space, it takes more trucks, which use more hydrocarbons. Increased use of hydrocarbons adds to smog levels. And none of the alternatives are cheaper. They are all two to five times more expensive.